Seasonal Climate Outlook Message for May to August 2000
The bottom line
The average SOI over the last 30 days was +12.9 . Based on the SOI, the probabilities of exceeding median rainfall during the total May to July period are little different from the 'normal' for this time of year in most of the eastern States of Australia, except for parts of southern NSW, western Victoria and eastern Tasmania where the probabilities are 60-70%.
More detailed information for your location can be obtained from the Australian Rainman software package. Also a lot of additional information is available on our FarmFax system, our Internet World Wide Web service called 'The Long Paddock', and on BoM's Fax and internet information services. Information contained in this publication is provided as general advice only. For application to specific circumstances, professional advice should be sought. The Department of Primary Industries, Queensland, has taken all reasonable steps to ensure the information in this publication is accurate at the time of publication. Readers should ensure that they make appropriate inquiries to determine whether new information is available on the particular subject matter.
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The full story
Review of Climatic Forecasts and Information
Based on the latest values and trends of the SOI, the probabilities of receiving above-median rainfall over the total April-June period are little different from the 'normal' for this time of year in most of the eastern States of Australia. Exceptions are parts of southern NSW, western Victoria and eastern Tasmania where the probabilities are 60-70%.
The persistent 'cool' sea-surface temperature (SST) anomalies are slowly contracting in the central and eastern equatorial Pacific Ocean, indicating that the La Niña pattern may be receding. This is also hinted at by other features associated with the La Niña, such as weakening of the strong easterly winds in the central Pacific.
Forecasts from most experimental general circulation models are currently suggesting that by mid-year the La Niña will have subsided and neutral conditions dominate. Sub-surface sea temperatures to the east of Australia are now significantly warmer than normal, in classic 'pre-El Nino' mode. In addition, some early research work suggests the sub-tropical ridge may again be further north than normal this winter which may tend to reduce winter rainfall from the Goondiwindi district through to the Central Highlands. As these indicators provide some cause for concern, regular monitoring of them and the SOI during the autumn 'predictability gap' is recommended.
Combining the rainfall outlook with current soil water and pasture condition, the probabilities of above-median pasture growth during the total March-May period are 60-100% in much of north Qld; 0-10% in much of far North Qld (maximum pasture growth has already been achieved); and 0-40% in much of the south-eastern corner of Qld.
The next passage of the 30-50 Day Oscillation over Queensland is expected about the second week in May.
